no need for that response. You've only been here 5 minutes. Pull your head in and have respect for the experience (time after time after time .....not one off) that you may benefit from on this site.
Despite the very rough welcome from some that think because they live on a forum that they have some ownership of the options that can be expressed, I agree with you that having someone place a baby in front of you is very poor form.
I think the cabin staff handled it well and reseated you.
FYI though, Empty J cabins to SIN are a rare thing these days since the move to DBX.